21Tell me, you who want to be under the law, do you not understand what the law says?
22For it is written that Abraham had two sons, one by the slave woman and the other by the free woman.
23His son by the slave woman was born according to the flesh, but his son by the free woman was born through the promise.
24These things serve as illustrations, for the women represent two covenants. One covenant is from Mount Sinai and bears children into slavery: This is Hagar.
25Now Hagar stands for Mount Sinai in Arabia and corresponds to the present-day Jerusalem, because she is in slavery with her children.
26But the Jerusalem above is free, and she is our mother.
27For it is written: “Rejoice, O barren woman, who bears no children; break forth and cry aloud, you who have never travailed; because more are the children of the desolate woman than of her who has a husband.”
28Now you, brothers, like Isaac, are children of promise.
29At that time, however, the son born by the flesh persecuted the son born by the Spirit. It is the same now.
30But what does the Scripture say? “Expel the slave woman and her son, for the slave woman’s son will never share in the inheritance with the free woman’s son.”
31Therefore, brothers, we are not children of the slave woman, but of the free woman.